Table of Contents
Advertisement
IX. Hydronic Piping (continued)
b. The TDS (in ppm) is determined by measuring the
electrical conductivity (µS/cm) of the water and
multiplying by a conversion factor (typically 0.65
for drinking water).
6. Chlorine and Chloride can be very corrosive to
stainless steel. Ensure the level of chlorine is less
than 5 ppm and the level of chloride is less than
1000 ppm.
7. Before connecting the boiler, insure the system is
free of impurities, grease, sediment, construction
dust, and any residual boiler water additives.
a. Flush the system thoroughly and repeatedly, if
needed, with clear water mixed with concentrated
rinse agent to remove these contaminants
completely.
Water temperatures over 140 °F (60 °C) greatly
increase the affects of corrosive chemicals.
Chlorine and Chloride have different levels
of corrosion effects on stainless steel. It is
recommended for chlorine (Cl2) levels to be below
5ppm and chloride (Cl
ppm for 316 stainless steel.
G. Oxygen Contamination
1. Continuous addition of make-up water will
constantly add oxygen to the system and lead
to corrosion. Black oxide sludge (magnetite,
Fe3O4) forms as a result of continuous electrolytic
corrosion in any system unprotected by an inhibitor.
2. To minimize oxygen presence in the system, all
system leaks must be repaired immediately. DO
NOT connect the boiler to radiant tubing without
an oxygen barrier.
3. There are many possible causes of oxygen
contamination such as:
a. Addition of excessive make-up water as a result
of system leak
b. Absorption through open tanks and fittings.
c. Oxygen permeable materials in the distribution
system.
4. In order to insure long product life, oxygen sources
must be eliminated. This could be accomplished by
taking the following measures:
a. Repairing system leaks to eliminate the need for
addition of make-up water.
b. Eliminate and/or repair fittings which allow
oxygen absorption.
c. Use of non-permeable materials in the distribution
system.
d. Isolating the boiler from the system water using
an indirect heat exchanger.
e. Using properly designed air elimination devices
in water piping.
43
NOTICE
NOTICE
) levels to be below 1000
-
Advertisement
Table of Contents
